How to fix “service unavailable” DNS failure

6 min read

Few people today realize just how complex the modern internet infrastructure is. So it’s really amazing that we can access any website or web app in the world from any device without any issues 99% of the time. 

It’s the 1%, however, that turns a seamless experience into technical problems. Such are various DNS errors, for example, that can range from “service unavailable” to “DNS not responding” to “DNS address could not be found.” 

So what do you do when you find your DNS server not responding? Here, we’ve collected the best tips for how to fix DNS issues. But first, let’s recap what a DNS error even is. 

What is a DNS failure? 

DNS stands for domain name system. It’s essentially an internet-wide database that transforms URLs, such as, into IP addresses, such as 

When you see a message like “DNS unavailable” that could mean that either your computer is struggling to reach a DNS server, or the DNS server is struggling to reach the target website. Both of these things could happen for a variety of reasons. 

So what do you do to fix DNS errors? 

How to troubleshoot DNS failures

While you can potentially change your ISP if DNS issues keep coming up, you can’t do much more about it than that at the macro level. 

You can do so much more, however, on your Mac. From clearing your cache to disabling extra connections to changing DNS settings. If you get a service unavailable DNS failure, try these steps one by one. 

1. Restart your Mac

The easiest solution to most problems on your Mac is either to restart the device or quit and open again the particular app you’re having problems with (e.g. your browser). 

2. Restart your modem or router

Since your modem is involved in all data that goes through your internet network, restarting it might also resolve DNS errors. Simply find the restart button on the back of your modem. 

Besides, you can turn your WiFi on Mac off and on. If you use an Ethernet cable, try disconnecting and reconnecting it back. 

In case you’re relying on any Bluetooth network devices, you can easily manage them with AirBuddy.

AirBuddy is a handy utility that keeps track of all wireless devices you use with your Mac, from headphones to WiFi extenders. Connect to and disconnect from any device in one click, monitor battery levels (with alerts), set your own shortcuts, and switch devices between several Macs — all from your menu bar. 

keeps track of all wireless devices

3. Switch to a different browser

Sometimes, for a variety of reasons, DNS connections might work slightly differently in various browsers. So if you have another browser installed on your Mac, try using it to connect to the website you want. 

Do you have too many browsers and tabs to keep track of? Navigate them all instantly with Tab Finder. 

Tab Finder presents all tabs from all your browsers in a single list. This utility is always easily accessible in your menu bar and you can also call it up with a shortcut at any time. No matter how many tabs you have running across any number of browsers, Tab Finder keeps everything accessible and neatly organized. 

all tabs from all your browsers

4. Clear your browser and DNS cache

If you can’t connect to a certain website, chances are, your browser cache might be working incorrectly. You can clear the browser cache in most browsers. 

To delete cache in Safari: 

  1. Open Safari Preferences (⌘ + ,)
  2. Switch to the Privacy tab
  3. Click Manage Website Data…
  4. Remove All

clear the browser cache

Other browsers have a similar workflow. But what if you could delete cache from everywhere in a single click? You can, with CleanMyMac X. 

CleanMyMac X is an all-in-one app for cleaning, optimizing, and protecting your Mac. Even with casual use, your Mac tends to accumulate lots of bugs, inconsistencies, and useless files. 

With CleanMyMac X, you can quickly choose a scan for a particular area of interest (e.g. malware or system junk) and get your Mac in shape in just one click. 

To clear browser cache, for example: 

  1. Launch CleanMyMac X
  2. Navigate to Privacy
  3. Click Scan
  4. Select all browsers you’d like to delete cache from
  5. Click Remove

clear the cache on all your browsers at once

Similarly, you can use CleanMyMac X to flush your DNS cache: 

  1. Navigate to the Maintenance tab
  2. Select Flush DNS Cache
  3. Click Run

Flush DNS Cache

5. Disable other network connections

In some cases, a DNS error might be a sign of conflicting network connections. Turning off Ethernet or Thunderbolt connections might help, as well as disabling Bluetooth. 

If you’re not sure which networks currently have access to your Mac, you can quickly check it with iStat Menus.

iStat Menus is a comprehensive monitoring system for your Mac. At a glance, you can see everything that’s going on, from networks to CPU to memory — right in your menu bar. It’s the easiest way to control your Mac. 

To see all network connections with iStat Menus, simply click on the network module. If you can’t disable any network connections, try refreshing your IP address, which you can do from the same menu. 

monitor network connection

6. Enable DNS filtering

The modern web is full of ads, annoying pop-ups, chats, trackers, autoplay videos, and other distractions. 

What’s more, the ad blockers are becoming less and less effective at getting rid of all the spam online. The solution is to use an ad blocker that enables DNS filtering, which could also resolve your DNS failure errors at the same time. 

AdLock is a unique, hands-off ad-blocking solution that works through DNS traffic filtering. Just launch the app and select to either not filter, filter, or block traffic for every browser. Then enjoy a better internet with no DNS errors and intrusive ads. 

DNS filtering

7. Use a VPN 

If DNS issues keep persisting after all the changes above, the problem might be at the ISP level, with its DNS server not resolving queries correctly. A great solution that adds even more privacy to your workflow would be to install and use a VPN. 

ClearVPN is one of the most intuitive VPNs on the market today. Just launch the app and choose what you want to do from a variety of shortcuts, whether it’s changing your location or blocking ads.

When you use a VPN, your DNS requests automatically go to the VPN’s server, which should resolve your DNS errors and improve your privacy.

vpn for Mac

As you can see, when you face a DNS server not responding, it’s not the end of the world. In fact, you can fix it quickly by disconnecting wireless devices with AirBuddy, managing your browser properly with Tab Finder, clearing cache with CleanMyMac X, refreshing your IP with iStat Menus, filtering your DNS with AdLock, or changing your DNS server completely with ClearVPN.

Best of all, AirBuddy, Tab Finder, CleanMyMac X, iStat Menus, AdLock, and ClearVPN are available to you absolutely free for seven days through the trial of Setapp, a platform with more than 230 outstanding Mac and iOS apps for every task you can imagine. Try every single one at no cost and master your Mac once and for all.

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